Space Charge Study on Printed Circuit Board Substrates for High Voltage Applications

space charge profiles of four different types of dielectric materials used as substrate in printed circuit board were measured using pulsed electroacoustic method. The measurements have been done under 10 kV/mm DC electric field at 25 °C and 50 °C, respectively. The experimental results showed that PTFE applied as substrates has the maximum amount of space charge accumulation and consequently local electric field enhancement at both temperatures. In contrast, FR4 presented the best results with a great performance in terms of space charge suppression. Therefore, the electric field distribution in FR4 is uniform with local electric field enhancement less than 10%. The results also showed suppressed space charge in the ceramic-base PCBs investigated, although the suppression appeared decreased with the temperature rise.